problems sending from a gui to a database
Hi again, I'm having problems adding to a database. In my gui I write the name of a product that is already in the database, then write how many items I want to sell of this product. When I press the send button it is supposed to be added to the table sales in the database that exists of 3 columns, PID, SID and amount.
I always get an error (For input String=""), and the error comes this class
elseif (input.equalsIgnoreCase("addSales"))
{
name = read.readLine();
amount = read.readLine();
try
{
int mAmount = Integer.parseInt(amount);
mAppl.addSale(name,mAmount);
}
catch(Exception e)
{
System.err.println(e.getMessage());
}}
This is a part of my GUI class
privateclass AddProductButtonListenerimplements ActionListener{
publicvoid actionPerformed(ActionEvent e){
outThread.addProduct(nameSaleField.getText(), amountField.getText());
outThread.setChoice("2");
}
}
publicclass OutputThreadextends Thread
{
PrintWriter write;
protectedstatic Socket out;
protectedstatic DataOutputStream output;
protected String choice ="";
protected String newProduct ="";
protected String newPrice ="";
protected String newAmount ="";
public OutputThread (Socket clientSocket){
out = clientSocket;
write =null;
}
publicvoid setChoice(String choice)
{
this.choice = choice;
}
publicvoid addProduct(String newProduct, String newPrice)
{
this.newProduct= newProduct;
this.newPrice = newPrice;
}
publicvoid addSales (String newProduct, String newAmount)
{
this.newProduct = newProduct;
this.newAmount = newAmount;
}
protectedstaticvoid initialize()
{
try
{
output =new DataOutputStream(out.getOutputStream());
}
catch(IOException e)
{
System.out.println(e.getMessage());
}
}
publicvoid sendData(double data)
{
try
{
output.writeDouble(data);
}
catch(IOException e)
{
System.out.println(e.getMessage());
}
}
publicvoid run(){
try
{
write =new PrintWriter(out.getOutputStream(),true);
}
catch (UnknownHostException e)
{
System.out.println(e.getMessage());
System.exit(1);
}
catch (IOException e){
System.err.println(e.getMessage());
System.exit(1);
}
try
{
BufferedReader stdIn =new BufferedReader(
new InputStreamReader(System.in));
String userInput;
while (!choice.equals(null)){
if(choice.equals("1"))
{
write.println("addProduct");
userInput = newProduct;
write.println(userInput);
userInput = newPrice;
write.println(userInput);
choice ="0";
}
elseif(choice.equals("2"))
{
write.println("addSales");
userInput = newProduct;
write.println(userInput);
userInput = newAmount;
write.println(userInput);
choice ="0";
}
elseif(choice.equals("3"))
{
write.println("getTotalValue");
choice ="0";
}
}}
catch(Exception e)
{
System.out.println(e.getMessage());
}}}
publicsynchronizedvoid addSale(String mName,int amount)throws SQLException
{
Statement stmt = con.createStatement();
int pid = 0;
ResultSet rs = stmt.executeQuery("Select PID from products where name='"+ mName +"'");
while(rs.next())
{
pid = rs.getInt("PID");
}
{
stmt.executeUpdate("insert into sales (PID, amount) VALUES (" + pid +", " + amount +")");
}}
I don't know if these codes are enough for you to see my problem, but I hope so.
